For the priest's lips should keep knowledge
Or "shall keep knowledge", as the Septuagint and Vulgate Latin versions; or "do keep knowledge", as the Arabic version; and so the Syriac version, "for the lips of the priest drop knowledge"; all this is true of Christ our great High Priest; for as it was predicted of him, that his lips should keep knowledge, so they have kept it, and do keep it; not concealing it, but preserving it, and communicating it freely and openly; as he did to his disciples and followers when here on earth, and by them to others; and still does by his Spirit, giving to men the knowledge of themselves and state; the knowledge of himself, and the way of salvation by him, and of the truths of the Gospel: and they should seek the law at his mouth;
not the law of Moses, but the doctrine of grace, and any wholesome instruction and advice; which he is greatly qualified to give, being the wonderful Counsellor: it may be rendered, "they shall seek", or "do seek"; and which has been fulfilled, especially in the Gentiles, and in the isles that waited for his law or doctrine, ( Isaiah 11:10 ) ( 42:4 ) : for he [is] the messenger of the Lord of hosts;
or "angel" F23; he is the Angel of God's presence, and of the covenant, ( Isaiah 63:9 ) ( Malachi 3:1 ) which name he has from being sent, for he came not of himself, but his Father sent him; he was sent as a priest to atone for the sins of his people, and to be their Saviour; and as a prophet, to instruct and teach them; and therefore they should seek to him for knowledge, and attend his word and ordinances, and implore his spirit and grace.
The Brenton translation of the Septuagint is in the public domain.